Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn.
Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn.
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DOI：
10.1371/journal.pone.0169115
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Finkenbinder C
中科院分区：
文献类型：
--
作者：
Dively GP;Venugopal PD;Finkenbinder C
利用表达苏云金芽孢杆菌（Bacillus thuringiensis, Berliner） （Bt）杀虫毒素的基因进行转基因玉米工程改造，是目前害虫治理的主要工具。随着Bt转基因技术的广泛应用，昆虫抗性已成为Bt转基因技术可持续发展的主要威胁。对于所有表达Cry毒素的Bt玉米，对Bt毒素更耐受的玉米耳虫Helicoverpa zea （Boddie）没有达到抗性管理的高剂量要求。我们利用Cry1Ab（1996-2016）和Cry1A.105+Cry2Ab2（2010-2016）表达的甜玉米杂交种作为田间筛选材料，提供田间监测数据，以测量田间药效的变化和对玉米蚜的Cry毒素敏感性。Cry1Ab-event Bt11和Cry1A.105+ Cry2Ab2-event MON89034两种Bt杂交品种自商业引进以来，幼虫成功侵染穗的比例增加，侵染核面积增加，发育阶段较晚（4 ~ 6龄）。玉米玉米种群丰度的年分布与防治效果的降低无关。没有证据表明不同Cry1Ab杂交种之间的田间药效或组织毒性存在差异，这可能导致防治效果下降。来自实验室生物分析的支持性数据表明，马里兰玉米玉米玉米菌株和敏感菌株在体重增加和适应性特征方面存在显著差异。在用Cry1Ab表达绿叶组织进行的生物测定中，在所有浓度下，马里兰玉米玉米玉米菌株都比敏感菌株增重更多。结果表明，马里兰玉米蚜品系的适宜度显著低于敏感品系，表现为孵化率低、成虫羽化时间长、蛹重低、成虫存活率低。在排除了可能的影响因素后，近年来玉米玉米玉米田间药效的快速变化和对Bt甜玉米的敏感性下降，为玉米玉米玉米玉米种群对多种Cry毒素的田间进化抗性提供了强有力的证据。Bt作物玉米和棉花的高采用率，以及Cry1Ab和相关Cry毒素在这些作物中的适度表达，以及避难所依从性的降低可能是抗性进化的原因。我们的研究结果对抗性监测、庇护要求和其他监管政策、交叉抗性问题以及金字塔Bt技术的可持续性具有重要意义。
Transgenic corn engineered with genes expressing insecticidal toxins from the bacterium Bacillus thuringiensis (Berliner) (Bt) are now a major tool in insect pest management. With its widespread use, insect resistance is a major threat to the sustainability of the Bt transgenic technology. For all Bt corn expressing Cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, Helicoverpa zea (Boddie), which is more tolerant to the Bt toxins. We present field monitoring data using Cry1Ab (1996–2016) and Cry1A.105+Cry2Ab2 (2010–2016) expressing sweet corn hybrids as in-field screens to measure changes in field efficacy and Cry toxin susceptibility to H. zea. Larvae successfully damaged an increasing proportion of ears, consumed more kernel area, and reached later developmental stages (4th - 6th instars) in both types of Bt hybrids (Cry1Ab—event Bt11, and Cry1A.105+Cry2Ab2—event MON89034) since their commercial introduction. Yearly patterns of H. zea population abundance were unrelated to reductions in control efficacy. There was no evidence of field efficacy or tissue toxicity differences among different Cry1Ab hybrids that could contribute to the decline in control efficacy. Supportive data from laboratory bioassays demonstrate significant differences in weight gain and fitness characteristics between the Maryland H. zea strain and a susceptible strain. In bioassays with Cry1Ab expressing green leaf tissue, Maryland H. zea strain gained more weight than the susceptible strain at all concentrations tested. Fitness of the Maryland H. zea strain was significantly lower than that of the susceptible strain as indicated by lower hatch rate, longer time to adult eclosion, lower pupal weight, and reduced survival to adulthood. After ruling out possible contributing factors, the rapid change in field efficacy in recent years and decreased susceptibility of H. zea to Bt sweet corn provide strong evidence of field-evolved resistance in H. zea populations to multiple Cry toxins. The high adoption rate of Bt field corn and cotton, along with the moderate dose expression of Cry1Ab and related Cry toxins in these crops, and decreasing refuge compliance probably contributed to the evolution of resistance. Our results have important implications for resistance monitoring, refuge requirements and other regulatory policies, cross-resistance issues, and the sustainability of the pyramided Bt technology.
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影响因子：
3.7
作者：
Gassmann AJ;Petzold-Maxwell JL;Keweshan RS;Dunbar MW
通讯作者：
Dunbar MW
影响因子：
2.2
作者：
Burkness, Eric C.;Hutchison, W. D.
通讯作者：
Hutchison, W. D.
DOI：
10.4161/gmcr.1.5.14765
发表时间：
2010-11-01
期刊：
GM crops
影响因子：
--
作者：
Burkness, Eric C;Dively, Galen;Hutchison, William D
通讯作者：
Hutchison, William D
影响因子：
3.7
作者：
Bernardi D;Salmeron E;Horikoshi RJ;Bernardi O;Dourado PM;Carvalho RA;Martinelli S;Head GP;Omoto C
通讯作者：
Omoto C
影响因子：
4.6
作者：
Brévault T;Tabashnik BE;Carrière Y
通讯作者：
Carrière Y